Field of the Invention
The present invention relates to a screwing system employed in an assembly system using a robot.
Description of the Related Art
In the manufacturing industry, a system of manufacturing a product includes a line production system and a cell production system. As in these systems, parts are generally conveyed by a robot or a person and manually assembled. In recent years, there has been demanded an assembly system which realizes a manual assembling operation by a robot. Especially, there has been demanded an assembly system in which a robot performs screwing and application. Furthermore, if an assembling operation is performed by a robot instead of a person, reduction in takt time, equipment cost, and installation space has been expected.
In the related art, an assembly system employing manual and robot assembling operations together is known, as disclosed in Japanese Patent Application Laid-Open No. 2004-66372. In the assembly system, a robot performs processes of assembling, screwing, and application, and a person conveys parts each time one of the processes is finished.
The screwing process in the assembly system is performed in a screwing system including a screw feeder, a screwing device, and a workbench. A first step of screwing is to place a part to be screwed on the workbench by a person. After the part is placed on the workbench, the screwing device moves to the screw feeder to obtain a screw, moves to a screwing position, and then screws the positioned part.
However, in the screwing system of the related art, a long takt time may be taken for an operation of placing the part on the workbench by a person and an operation of taking out the screwed part. A robot may perform the operation in a similar manner to a person.
Moreover, in order to tighten a plurality of screws which have different postures, another screwing system needs to be introduced, or a plurality of driving shafts needs to be added so as to change a posture of the workbench or the screw fastener. This may increase the cost. Not only that, the introduction of another screwing system and the increase in the number of driving shafts lead to opening of a new production line and an increase in installation space.